ABUS-SG1650-Optic-Acoustic-Combination-Signal-Transmitter-Abus-SG1650-P-The-ABUS-SG1650-Optic-Acoustic-Combination-Signal-Transmitter-can-be-mounted-inside-&-outside-your-building-&-plays-a-crucial-link-of-a-fully-functioning-alarm-chain-In-the-event-of-an-alarm-the-alarm-sounder-generates-an-extremely-loud-signal-tone-with-over-110d B-sound-pressure-P-P-In-addition-to-the-audible-alarm-there-is-an-optical-alert-from-a-red-Xenon-strobe-light-that-is-visible-over-long-distances-1-1